Gaseous bischarge tube circuit



Aug-11,1936 R. M. CRITCHFIELD 2 2,050,922

GASEOUS DISCHARGE TUBE CIRCUIT Original Filed Dec. 31, 1930 INVENTOR ATTORNEY Patented Aug. 11, 1936 PATENT OFFICE GASEOUS EISCHARGE TUBE CIRCUIT Robert M. Crltchfleld, Anderson, Ind., assignor,

by mesne assignments, to General Motors @Uo'rpora'tion, Detroit, Mich, a corporation of Delaware @riglnal application December 31, 1930, Serial Divided and this application All: 4, 1933, Serial No. 683,572

2 Claims.

This invention relates to a circuit for producing a high alternating potential, from a low voltagevsource, and more particularly to a ciredit for operating gaseous discharge'tubes and similar apparatus requiring relatively high voltage. This application is a division of my copending application Serial Number 505,787, which application has become Patent No. 1,952,- 121.

It is one of theobjects of the present, invention 'to provide a circuit for theoperation of gaseous discharge tubes and similar apparatus that is especially adapted for use on automotive vehicles or in other places equipped with a current source of relatively low voltage. This aim of the present invention is carried out by providing a circuit including induction apparatus in which electrical energy from a relatively low voltage source is interrupted and transformed to a relatively high voltage in order to supplya a rapid succession of relatively high voltage impulses suitable for operating a gaseous discharge tube or similar apparatus. The interruption of the current from the low voltage source that is supplied to an induction coil to be transformed to a higher voltage is efiected by a periodic circuit; breaker that is preferably operated by an. electricmotor. The motor, as well as the gaseous discharge tube, is preferably supplied with operating current from the low voltage source, which source may be a storage battery or the generator that charges the storage battery.

Another object of the present invention is to provide a clrcuitfor the operation of a plurality of gaseous discharge tubes, or similar devices requiring a relatively high operating voltage, 'Irom a single low voltage source, and with only a single current interrupting device. This aim of the present invention is carried out by providlng a circuit that permits the interruption of the current to a plurality of induction coils by a single current interrupter, each of which induction coils provides the high operating voltbodiment of one form of the present invention is clearly shown.

In the drawing: Pig. 1 is a schematic diagram of a circuit em bodying the present invention.

Fig. 2 is a schematic diagram showing a modiiled form of the present invention that vis adapted to supply current to two gaseous discharge tubes.

With particular reference to Fig. 1, an induction coil 2!, that may be an ignition coil, has a primary winding 22 and a secondary winding 23. One terminal 24 of the-winding 22 is connected by a wire 25 to a terminal 26, and through a fuse 28 to a switch contact 30. The switch contact 30 is adapted to be'connected through a switch arm ii to one side of a battery 32, the other side of which battery is grounded at. The other; terminal 34 of the winding; 22 is connected by a wire 35 to a terminal 36 of a condenser 31. The other terminal of the condenser 31 is grounded at 38.

- The terminal 38' is also connected by a wire 39 circuit breaker lever 42 that is pivoted at 3.

The spring H electrically connects the terminal M with the lever 42, urges the rubbing block 44 against the cam and urges a contact 46 that is carried by the lever or into engagement with a stationary contact ll that is grounded at 39.

The secondary winding 93 has one of its ends connected to the terminal 2- 5 of the primary winding 22, and is thus'grounded through the wire 25,1use 23 and battery 32 to ground at 33. The other end of the secondary winding 23 is connected to a terminal to, and a conductor 5|, that is preferably an insulated cable, to a gaseous discharge tube 52, which gaseous discharge tube is connected to ground at 53. The tern'nnal to is connected with a wire to, the end of which wire is spaced irom the terminal 24 to provide a safety spark gap 55. I

. An electric motor 50, that is preferably small, having brushes it and H and a field winding 63, is drivingly connected to the cam 45 by a shaft or other suitable driving means 56. The brush I0 is connected to the terminal 26 and to one end of the field winding 63. The other brush H is grounded at 15, and is connected to the other end of the field winding 53.

.When the switch arm 3| engages the contact 30, the battery 32 is connected to the motor and to the induction coil 2|. The rotor rotates,

preferably at high speed, to actuate the cam 45, and breaker lever 42, and thereby effects the alternate closing and opening of the contacts 46 and 41, which opening and closing 01 the contacts interrupts the circuit between the primary winding 22 and ground at w. This interruption of the circuit of the primary winding 22 is preferably periodic, and causes a series of current impulses through the primary winding 22, which current impulses produce a high voltage impulse across the secondary winding 23 when the contacts are opened. By thus generating a. rapid succession of high voltage impulses which are conducted from the secondary winding 23 to the gaseous discharge tube 52, the gas within the tube is caused to become incandescent.

The wiring diagram in Fig. 2 discloses the manner of using one motor and periodic circuit breaker to control a plurality of induction coils, each of which coils supplies high voltage impulses to a gaseous discharge tube. V

In Fig. 2, parts corresponding to the parts in Fig. 1 are referred to by similar reference characters with the afiix a. the primary windings 22a and 22b'of the-two induction coils Ma and 2lb are connected together in series with the circuit interrupter and with a battery having a voltage greater than that of the battery 32 required for operating one gaseous discharge tube. Each of the secondary windings of the induction coils is connected to a gaseous discharge tube. Since it requires no more power to operate a circuit interrupter which controls two coils than it does for operating the circuit interrupter which controls one coil, the same motor can be used for driving the circuit interrupter of Fig. 2 as was used in Fig. '1. Therefore, this motor is not connected with all of the cells of the battery 32a, but with only a sufiicient numberof them to operate the motor. For example, if a 12 volt battery is required to operate both induction coils Zia and 21b, and a. 6 volt motor is used, as indicated in Fig. 2, the motor 60 is not connected with the wire 25a. as in the preceding case, but is connected by a separate electric switch 9!] to an intermediate tap 9! of the battery 32a, switch 90 being operated concurrently with aswitch 3m. While the form of invention shown in Fig. 2 is illustrated with two separate gaseous discharge tubes, it will be understood that this form of apparatus can be used for lighting separate sections of a gaseous discharge device. For example, if one induction coil operated by a 6 volt battery will supply the necessary potential and current for operating one gaseous discharge device or section of a certain size and filled with a certain kind of gas, and a larger device or more sections are necessary, the sections will be so divided that each is capable of being operated by a 6 volt induction coil. When a plurality of gaseous discharge devices or a plurality of sec= tions are used, an induction coil is provided for each of the section or number of devices that it is capable of operating, and the primary winding of these coils may be connected in series or in series parallel to a suitable source of operating potential.

While the present specification describes the operation of the circuit with particular reference to gaseous discharge tubes, it is understood that the invention is applicable to other devices requiring an alternating potential of relatively high voltage.

It will be noted that current and the circuit interrupter being conaccuses From the aforegoing description of the construction and operation of the present igniting circuit for gaseous discharge tubes, it will be apparent that the circuit, in one of its principal aspects, comprises a plurality of high tension 5 gaseous discharge tubes 52a and 52b, a plurality of transformers Zia and 2lb eachincluding a. primary winding 22a and 2217 respectively and a secondary winding 23a. and 23b respectively, and each (Ma and 2m having one end of the primary winding 22a and 22b respectively electrically connected to one end of the secondary winding 23a and 23b respectively, a source of direct current 32a, and a circuit interrupter 88a, "a, the primary windings 22a and 22b,'the source of direct 15 current 32a and the circuit interrupter 46a and 4111 being connected in series and each of the gaseous discharge tubes 52a, 521;, being ignited by the potential across only one of the secondary windings 23a and 23b respectively.

Some of the advantages of the circuit herein disclosed and described are as follows:

(1) A plurality of gaseous discharge tubes may be ignited from a common current source, and have potentials individually applied thereto so 25 that the operation of one tube is not dependent upon that of the other.

(2) The series connection of the primary windings, current source and circuit interrupter in the igniting circuit permits the use of a com- 30 mon current source and interrupter for the plurality of transformers and gaseous discharge tubes, and also effects low current consumption with the high ratio transformers.

(3) The electrical connection of the primary 35 windings of each transformer to the secondary windings thereof makes-possible the use of a common ground or connection in the circuit for igniting the plurality of gaseous discharge tubes. While the form oi embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as iollows: 1. As an igniting circuit for gaseous discharge tubes, the combination comprising, a plurality of high tension gaseous dischargetubes, a plurality of transformers each including a primary winding and a secondary winding and each having one end of the primary winding electrically connected to one end of the secondary winding, a source of direct current, and a circuit interrupter, the primary windings, the source of direct nected in series and each of the gaseous dis charge tubes being ignited by the potential across only one of the secondary windings;

2. In a gaseous'discharge tube igniting circuit, the combination of a plurality of high tension electrical discharge tubes, a plurality of transformers, each including .a primary winding and a secondary winding, 2. source of potential, and l a circuit interrupter, all of the primary coils, the source of potentiaLand the circuit interrupter being connected in a series circuit, and each of the high tension discharge tubes being energized by one only of the secondary coils.

ROBERT M. CRITCEE'IELD. 

